Musings in the life of an internist, cardiologist and cardiac electrophysiologist.

Thursday, November 08, 2007

Vindicated

Sorry, but after all the trash-talk I received from members of a certain financial board regarding my decision not to purchase Cambridge Heart's T-wave alternans test previously, I'm feeling a bit vindicated right now.

4 comments:

Mani
said...

Hello Dr. Wes,You blog was displayed on the google finance page for CAMH and I thought I would check it out.

MTWA seems interesting. I need to read a bit more about it. However after reading your blog and also a couple of message boards dedicated to CAMH, I have a question. Are the ICD manufacturers really against MTWA as most people claim on the message boards. I'm confused because in one your blogs you say "the increased screening using this test might actually INCREASE the number of implanted devices" which kind of explains why STJ may buy a stake in the company. Why haven't other ICD companies wholeheartedly embraced the technology then? I think i am missing something here.

wow, i don't know how i missed the mtwa comments. kudos to you for keeping your cool despite inflammatory comments, dr wes.fwiw, my practice and the 3 practices i keep in close contact with (representing a total of 18 ep physicians) in the last year voted pretty unanimously to wait for more data before purchasing/recommending its use.

Most tests give results that are considered either "positive" or "negative." Depending on the quality of the test, they will either correctly determine the disease is present ("true positive") or think the disease is present when it is not ("false positive"). Likewise, the test could correctly determine the disease is absent ("true negative") or think the disease is not there when, in fact, it is present ("false negative").

A positive test, then, will represent a certain number of "true positives" and "false positives." If the population screened in large, these "positive" tests would mount and would imply an therapy should be rendered, but if the number of false positives is large, then MORE tests might be applied to the population than would be without the test.

In the case of MTWA testing, "positive" patients would be recommended to have ICD implants. If you screen enough people, there will certainly be lots of "true positives" but also many "false positives" as well and this number might actually be larger than the number of patients being implanted presently. This is why St. Jude and Medtronic were hoping this would jump-start their ICD implant volume.

About Me

Westby G. Fisher, MD, FACC is a board certified internist, cardiologist, and cardiac electrophysiologist (doctor specializing in heart rhythm disorders) practicing at NorthShore University HealthSystem in Evanston, IL, USA and is a Clinical Associate Professor of Medicine at University of Chicago's Pritzker School of Medicine. He entered the blog-o-sphere in November, 2005.
DISCLAIMER: The opinions expressed in this blog are strictly the those of the author(s) and should not be construed as the opinion(s) or policy(ies) of NorthShore University HealthSystem, nor recommendations for your care or anyone else's. Please seek professional guidance instead.